Friday, October 29, 2010

The Stone is the new section of the New York Times devoted to philosophy and this week it contains an interesting piece called “Stories vs. Statistics” by John Allen Paulos. It is worth reading in its entirety, but for my money the most important point he makes is this:

The more details there are about them in a story, the more plausible the account often seems. More plausible, but less probable. In fact, the more details there are in a story, the less likely it is that the conjunction of all of them is true.

Our tendency to confuse plausibility with probability is also at the heart of a short essay of mine (forthcoming in the journal Think), called “Beware the Convincing Explanation.” Paulos clarifies the excerpt above by reference to the ‘conjunction fallacy,’ which I discussed in an earlier post. In my essay I try to get at it from a different angle, by distinguishing the respective functions of argument and explanation.

Here is the basic idea: Normally, when we ask for an argument we are asking for evidence, which is to say the grounds for believing some claim to be true. An explanation, on the other hand, is not meant to provide grounds for belief; rather it tells us why something we already believe is so. Almost everyone understands this distinction at an intuitive level. For example, suppose you and I were to have this conversation about our mutual friend Toni.

Me: Boy, Toni is seriously upset.

You: Really? Why?

Me: She’s out in the street screaming and throwing things at Jake.

You can tell immediately that we aren’t communicating. You asked for an explanation, the reason Toni is upset. What I gave you is an argument, my reasons for believing she is upset. But now consider a conversation in which the converse error occurs:

Me: Boy, Toni is seriously upset.

You: Really? How do you know that?

Me: Jake forgot their date tonight and went drinking with his pals.

This time my response actually begs the question. Jake blowing off the date would certainly explain why Toni is upset, but an explanation is only appropriate if we agree that she is. Since your question was a request for evidence, it is clear that you are not yet convinced of this and I’ve jumped the gun by explaining what caused it.

What’s interesting is that people do not notice this so readily. In other words, we often let clearly explanatory locutions pass for arguments. This little fact turns out to be extremely important, as it makes us vulnerable to people who know how to exploit it. For example, chiropractic medicine, homeopathy, faith healing -- not to mention lots of mainstream diagnostic techniques and treatments -- are well known to provide little or no benefit to the consumer. Yet their practitioners produce legions of loyal customers on the strength of their ability to provide convincing explanations of how their methods work. If we were optimally designed for detecting nonsense, we would be highly sensitive to people explaining non-existent facts. We aren’t.

Now, to be fair, there is a sense in which causes can satisfy evidential requirements. After all, Jake blowing off the date can be construed as evidence that Toni will be upset when she finds out. However, it is quite weak evidence compared to actually watching Toni go off on him. So, we can put the point a bit more carefully by saying that what people don’t typically understand is how weak the evidence often is when an explanation gets repurposed as an argument.

Following Paulos, we can say that the convincing explanations succeed in spite of their evidential impotence because they are good stories that give us a satisfying feeling of understanding a complex situation. Importantly, this is a feeling that could not be sustained if we were to remain skeptical of the claim in question, as it is now integral to the story.

Belief in the absence of evidence is not the only epistemic mischief that explanations can produce. The presence or absence of an explanation can also inhibit belief formation in spite of strong supporting evidence. The inhibitory effect of explanation was demonstrated in a classic study by Anderson, Lepper and Ross which showed that people are more likely to persist in believing discredited information if they had previously produced hypotheses attempting to explain that information. Robyn Dawes has documented a substantial body of evidence for the claim that most of us are unmoved by statistical evidence unless it is accompanied by a good causal story. Of particular note are studies by Nancy Pennington and Reid Hastie which demonstrate a preference for stories over statistics in the decisions of juries.

Sherlock Holmes once warned Watson of the danger of the convincing explanation: “It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.” Damn good advice from one of the greatest story-tellers of all.

Thursday, October 28, 2010

Mad belief -- in David Lewis's sense of "mad" -- would be belief with none of the normal causes and none of the normal effects. Such belief, I suggest, would not be belief at all. Delusions might sometimes be cases of beliefs gone half-mad -- beliefs with enough of the functional role of belief that it's not quite right to say that the deluded subject believes but also diverging enough from the functional role of belief that it's not quite right simply to say that the subject fails to believe.

So I say, at least, in an essay now available in draft on my website. (As always, comments, revisions, objections welcome -- either attached to this post or emailed directly to me.)

Sunday, October 24, 2010

James Surowiecki recently wrote a nice full-length review of The Thief of Time for The New Yorker magazine. It sounds like a fantasy novel by Terry Pratchett, but is actually a collection of mostly pointy-headed philosophical essays about procrastination edited by Chrisoula Andreou and Mark White. Procrastination is a great topic if you are interested in the nature of irrationality, as philosophers and psychologists tend to think of procrastination as something that is irrational by definition. For example, in the lead article of this volume George Ainslie defines procrastination as “generally meaning to put off something burdensome or unpleasant, and to do so in a way that leaves you worse off.”

I recently published an article about cruelty in which I argued that it is a mistake for scientists to characterize the phenomenon of cruelty in a way that respects our basic sense that it is inherently evil. I find myself wondering whether the same sort of point might be raised against the scientific study of procrastination.

Most researchers appear to accept Ainslie’s characterization of procrastination as an instance of "hyperbolic discounting," which is an exaggeration of an otherwise defensible tendency to value temporally proximate goods over more distant ones. Everyone understands that there are situations (like a time-sensitive debt or investment opportunity) when it is rational to prefer to receive 100 dollars today rather than 110 dollars next week. But Ainslie and many others have demonstrated that we typically exhibit this preference even when it makes far more sense to wait for the larger sum.

Hyperbolic discounting subsumes procrastination in a straightforward way. According to Ainslie, whenever we procrastinate we are choosing a more immediately gratifying activity over one whose value can only be appreciated in the long run. When making plans a week in advance, few would choose to schedule the evening before a big exam catching up on neglected correspondence or deleting old computer files. But when the decision is left until then, that’s exactly the sort of thing we find ourselves doing.

One interesting result of defining procrastination as Ainslie does is that whether we are procrastinating at any given time depends on what happens later, not how we feel about it now. For example, reading this blog is something you might describe as procrastinating on cleaning your filthy apartment. But, according to Ainslie’s definition, you are only procrastinating now if you subsequently fail to get the apartment clean before your guests arrive for dinner (because otherwise you aren’t “worse off”). There is nothing absurd about this, and science certainly has no obligation to be faithful to ordinary usage. But this disparity does highlight an interesting possibility, namely that what Ainslie and his colleagues call procrastination is really just the downside of a generally rational tendency to avoid beginning onerous tasks much before they really, really need to be done.

Why would this be rational? Well, you could start cleaning your apartment right now. But- wait! -there is a good chance that if you do you will become the victim of Parkinson’s Law: Work expands so as to fill the time available for its completion. Putting it off until the last minute can be beneficial because you work much more energetically and efficiently when you are under the gun. (And if you don’t, then you will learn to, which is an important life skill.) Of course, this strategy occasionally backfires. We sometimes underestimate the time we need to meet our goals; unanticipated events, like a computer crashing or guests arriving early, can torpedo the deadlining strategy. But these exceptions, which are often uncritically taken as proof of the irrationality of procrastination, may simply be a reasonable price to pay for the value it delivers when it works.

Most of us think of procrastination as a bad thing and we tell researchers that we do it too much. But should this kind of self-reporting be trusted? Do we just know intuitively that we would be generally better off if we generally procrastinated less? Scientists can define procrastination as harmful if they want to, but they also might want to reconsider the wisdom of a definition that makes beneficial procrastination a logical absurdity. In doing so, they may discover that the powerful notion of hyperbolic discounting has made them too quick to accept a universal human tendency as a fundamentally irrational one.

Friday, October 15, 2010

Earlier today, the University of California regents unanimously voted to impose a new Air Consumption Fee on students, faculty, and staff. The new fee will go into effect on January 1.

University of California President Mark G. Yudof said, "Most people think of air as free, but they don't realize that it needs to be processed through ventilation systems." Ventilation systems, he added, "cost money both to build and to maintain. In times of economic difficulty for the University of California, we need to look carefully at costs, such as the cost of air."

The new Air Consumption Fee will be $1,210.83 per quarter for students on the quarter system and $1,816.25 per semester for students on the semester system. For faculty and staff, the Air Consumption Fee will be 23% of their base salary. University of California's chief economist for the Office of the President, Muss Erhaben, noted, "That may seem like a lot to pay for air, but recent studies have suggested that demand for air is relatively inelastic" and thus not very sensitive to changes in price.

Student, faculty, and staff advocacy groups were predictably outraged by the move. "The sudden imposition of new fees on students, especially in the middle of the academic year, creates enormous hardships, especially for students already in economic difficulty," commented U.C.L.A. student representative Tengo K. Respirar. "For example, I had been hoping for an iPad for Christmas. Instead, my parents will be buying me air."

Others complained that the fee was unfair to those who use less air. "I can stop my heart and breathing for minutes at a time and consume only a half cup of rice and thin broth every day," said Swami B. Retha Litla. "I should not be expected to pay the same as a football player." Donna M. de l'Air, a U.C. Riverside Associate Professor in Comparative Languages and Literatures, noted that the Air Consumption Fee will be deducted from her salary even though she will be on sabbatical in France for winter quarter, and thus will be consuming no University of California air. In response to this concern, a representative of the Office of the President stated that the University of California is working on exchange arrangements with other universities to ensure that professors and students in residence elsewhere will not be double-charged for air.

In related news, the U.C. regents also voted to institute a new tier for employees. Current employees who wish the university to abide by its previous salary and benefits agreements may elect to join the Traditional Plan tier at an annual cost of 50% of their salary. Alternatively, employees may elect to join the New Plan at no charge. The New Plan involves a 50% reduction in salary. "We are proud that in these difficult budgetary times we have been able to abide by all our agreements and avoid salary cuts, at least for staff who pay to join the Traditional Plan," said President Yudof.

Every teacher knows that magic moment when the light snaps on in a student’s head and bitter confusion gives way to the warm glow of understanding. We live for those moments. Subsequent moments can be slightly less magical, however. There is, for example, the moment we begin to grade said student’s exam, and realize that we’ve been had yet again by the faux glow of illusory understanding.

The reliability and significance of our sense of understanding (SOU) has been the subject of research in recent years. I indicated in the previous post that philosophers of science generally agree that there is a tight connection between explanation and understanding. Specifically, they agree that the basic function of explanation is to increase our understanding of the world. But this agreement is predicated on an objective sense of the term ‘understanding,’ typically referring to a more unified belief system or a more complete grasp of causal relations. There is no similar consensus concerning how our subjective SOU relates to ‘real’ understanding, or indeed whether it is of any philosophical interest at all.

One leading thinker who has argued for the relevance of the SOU to the theory of explanation is the developmental psychologist Alison Gopnik. Gopnik is a leading proponent of the view that the developing brains of children employ learning mechanisms that closely mirror the process of scientific inquiry. As the owner of this blog has aptly put it, Gopnik believes that children are invested with ‘a drive to explain,’ a drive she compares to the drive for sex.

For Gopnik, the SOU is functionally similar to an orgasm. It is a rewarding experience that occurs in conjunction with an activity that tends to enhance our reproductive fitness. So just as a full theory of reproductive behavior will show how orgasm contributes or our reproductive success, a full theory of explanatory cognition will show how the SOU contributes to our explanatory success.

Part of the reason Gopnik compares the SOU to the experience of orgasm is that they can both be detached from their respective biological purposes. Genital and theoretical masturbation are both pleasurable yet non (re)productive human activities. Gopnik thinks that just as no one would consider the high proportion of non reproductive orgasms as evidence that orgasm is unrelated to reproduction, no one should take a high frequency of illusory SOU’s as evidence that the SOU is unrelated to real understanding.

But the analogy between orgasm and the SOU has its limits. The SOU can not really be detached from acts of theorizing as easily as orgasm can be detached from acts of reproduction. One might achieve a free floating SOU as a result of meditation, mortification or drug use, but this will be relatively unusual in comparison to the ease and frequency with which orgasms can be achieved without reproductive sex. For the most part SOU’s come about as a result of unprotected intercourse with the world. If illusory SOU’s are common, and this can not be explained by reference to their detachability, it is reasonable to remain skeptical about the importance of the SOU in producing real understanding.

One such skeptic is the philosopher of science J. D. Trout. Trout does not deny that our SOU may sometimes result from real understanding, but he thinks it is the exception rather than the rule. Moreover, Trout thinks that illusory SOU’s are typically the result of two well-established cognitive biases: overconfidence and hindsight. (Overconfidence bias is the tendency to overestimate the likelihood that our judgments are correct. Hindsight bias is the tendency to believe that past events were more predictable than they really were.) Far from being a reliable indicator of real understanding, Trout holds that the SOU mostly reinforces a positive illusion we have about our own explanatory abilities. (This view also finds support in the empirical research of Frank Keil who has documented an ‘illusion of explanatory depth’)

Is it true that illusory SOU’s are more common than veridical ones? I’m not sure about this. I‘m inclined to think most of our daily explanatory episodes occur below the radar of philosophers of science. Consider explanations that occur simply as the result of the limits of memory. My dog is whining and it occurs to me that I haven’t fed her. The mail hasn’t been delivered, and then I recall it is a holiday. I see a ticket on my windshield and I remember that I didn’t feed the meter. I have an dull afternoon headache and realize I’ve only had three cups of coffee. These kinds of explanatory episodes occur multiple times every day. The resulting SOU’s are powerful and only rarely misleading.

But when choosing between competing hypotheses or evaluating explanations supplied by others Trout is surely correct that the intensity of an SOU has little to do with our degree of understanding. We experience very powerful SOU’s from just-so stories and folk explanations that have virtually no predictive value. Often a strong SOU is simply the result of the fact that it allays our fears or settles cognitive dissonance in an emotionally satisfying way.

In the end, I’m not sure that Trout and Gopnik have a serious disagreement. For one thing, Gopnik’s focus in on the value of the SOU for the developing mind of a child. It may be that the the unreflective minds of infants are uncorrupted by overconfidence, hindsight, or the need to believe. It may also be that a pre-linguistic child’s SOU is particularly well-calibrated for the kind of learning it is required to do.

Trout does not argue that the SOU is completely unreliable, and Gopnik only needs it to be reliable enough to have conferred a selective advantage on those whose beliefs are reinforced by it. There are different ways that this can happen. As Trout himself points out, the SOU may contribute to fitness simply by reinforcing the drive to explain. But even if our SOU is only a little better than chance at selecting the best available hypothesis at any given time, it could still be tremendously valuable as part of an iterated process that remains sensitive to negative feedback. As I indicated in the previous post, our mistake may be to think of the SOU as something that justifies us in believing our hypotheses. It may simply help us to generate or select hypotheses that are slightly more likely to be true than their competitors.

Tuesday, October 12, 2010

... still, almost two centuries later, has no scholarly-quality English translation of his (1830-1842) magnum opus, Cours de Philosophie Positive. This is, I think, rather a scandal for such an important philosopher.

(How important? Well, Dean Simonton's mid-20th-century measure of the historical importance of thousands of philosophers, according to textbook pages dedicated to them and similar measures, ranks him as the 17th most important philosopher in history, between Rousseau and Augustine -- though I'd guess that Anglophone philosophers in 2010 wouldn't rank him quite so high.)

The standard translation of Cours de Philosophie Positive is The Positive Philosophy of Auguste Comte, "freely translated and condensed by Harriet Martineau" in 1896. Wait, what?! Freely translated and condensed? What is this, the friggin' Reader's Digest version? You're not planning to quote from it, I hope.

Probably Comte's most famous contribution to philosophy of psychology is his brief argument against the possibility of a science of introspection. Here is Martineau's translation of the passage in which Comte lays out his argument:

In the same manner, the mind may observe all phenomena but its own. It may be said that a man's intellect may observe his passions, the seat of the reason being somewhat apart from that of the emotions in the brain; but there can be nothing like scientific observation of the passions, except from without, as the stir of the emotions disturbs the observing faculties more or less. It is yet more out of the question to make intellectual observation of intellectual processes. In order to observe, your intellect must pause from activity; yet it is this very activity that you want to observe. If you cannot effect the pause, you cannot observe: if you do effect it, there is nothing to observe (vol. 1, p. 12).

I won't inflict the original French upon you (it is available in Google books here, if you're interested), but for comparison here is William James's translation in his Principles of Psychology:

It is in fact evident that by an invincible necessity, the human mind can observe directly all phenomena except its own proper states. For by whom shall the observation be made? It is conceivable that a man might observe himself with respect to the passions that animate him, for the anatomical organs of passion are distinct from those whose function is observation. Though we have all made such observations on ourselves, they can never have much scientific value, and the best mode of knowing the passions will always be that of observing them from without; for every strong state of passion... is necessarily incompatible with the state of observation. But as for observing in the same way intellectual phenomena at the time of their actual presence, that is a manifest impossibility. The thinker cannot divide himself into two, of whom one reasons while other other observes him reason. The organ observed and the organ observing being, in this case, identical, how could observation take place? This pretended psychological method is then radically null and void. On the one hand, they advise you to isolate yourself, as far as possible, from every external sensation, especially every intellectual work, -- for if you were to busy yourself even with the simplest calculation, what would become of internal observation? -- on the other hand, after having with the utmost care attained this state of intellectual slumber, you must begin to contemplate the operations going on in your mind, when nothing there takes place! Our descendants will doubtless see such pretensions some day ridiculed upon the stage (1980/1981, p. 187-188).

(The ellipses above mark one phrase James omits: "c'est-à-dire précisément celui qu'il serait le plus essential d'examiner" which, in my imperfect French I would translate as "that is to say, precisely that which it would be the most essential to examine". It is perhaps also worth remarking that no emphasis on "passions" or "intellectual" appears in my edition of Comte, though "intérieure" is italicized.)

Not only does the Martineau translation lose the detail and the color of the original, it is philosophically and psychologically sloppy. For example, Comte makes no reference to the "brain" or the "seat of reason"; instead -- as James indicates -- he talks about "the organs... whose function is observation" ("les organes... destinés aux fonctions observatrices"). And what is this that Martineau says about "the stir of the emotions disturbs the observing faculties more or less"? There is no trace of this clause in the original text. Martineau has inserted into Comte's text an observation that she evidently thinks he should have made.

We should no longer cite Martineau's translation as though it were of scholarly quality. There is no scholarly translation of Comte's most important work.

Wednesday, October 06, 2010

One of my main interests is explanation. I think there may be no other concept that philosophers lean on so heavily, yet understand so poorly. Here are some examples of how critical the concept of explanation has become to contemporary philosophical debates.

1. A popular defense of scientific realism is that the existence of theoretical entities provides the best explanation of the success of the scientific enterprise.

4. A popular argument for the existence of God is that a divine intelligence is the best explanation of the observed order in the universe.

This is a short list. The concept of explanation has been invoked in similar ways to analyze the nature of knowledge, theories, reduction, belief revision, and abstract entities. Interestingly, few of the very smart people who defend these views tell us what explanation is. The reason is simple: we don’t really know. The dirty secret is that explanation is just no better understood than any of the things that explanation is invoked to explain. In fact, it is actually worse than that. If you spend some time studying the many different theories of explanation that have been developed during the last 60 years or so, you’ll find that most of them give little explicit support to these arguments.

The reason for this is worth knowing. Most philosophical theories of explanation have been developed in an attempt to identify the essential features of a good scientific explanation. The good-making features of explanation were generally agreed to be those that would account for how explanation produces (and expresses) scientific understanding. There are many different views about this, but an assumption common to most of them is that a good scientific explanation must be based on true theories and observations. That sounds pretty reasonable, but here’s the rub: If truth is a necessary condition of explanatory goodness, then it makes no sense at all to claim that a theory’s explanatory goodness is our basis for thinking it is true.

All of the arguments noted above do just this, invoking a principle commonly known as “inference to the best explanation” (IBE, aka ‘abduction’). This idea, first articulated by Charles Peirce, has been the hope of philosophy ever since W.V.O. Quine pounded the last nail into the coffin of classical empiricism. This latter tradition had sought in vain to demonstrate that inductive rationality could ultimately be reduced to logic. For many, IBE is a principle that, while not purely logical, might serve as a new ‘naturalized’ foundation of inductive rationality.

Bas van Fraassen, the great neo-positivist, has blown the whistle on IBE most loudly, arguing that it is actually irrational. One of his criticisms is quite simple: It is literally impossible to infer the best explanation; all we can infer is the best explanation we have come up with so far. It may just be the best of a bad lot.

One way to understand the disconnect between traditional theories of explanation and IBE is to note that there are two fundamentally different ways of thinking about explanation. In one, basically transactional sense, explanations are the sorts of things we seek from pre-existing reserves of expert knowledge. When we ask scientists why the night sky is dark or why it feels good to scratch an itch, we typically accept as true whatever empirical claims they make in answering our question. Our sense of the quality of the explanation is limited to how well we think this information has answered the question we’ve posed. This, I think, is the model implicit in most traditional theories of explanation. The aim is to show in what sense, beyond the mere truth of the claims, that science can be said to provide the best answers.

In my view, IBE has more to do with a second sense of explanation, belonging to the context of discovery rather than communication of expert knowledge. In this sense, explaining is a creative process of hypothesis formation in response to novel or otherwise surprising information. It can occur within a single individual, or within a group, but in either case it occurs because of the absence of authoritative answers. It is in this sense of the term that it can make sense to adopt a claim on the basis of its explanatory power.

Interestingly, much of the work done on transactional accounts of explanation is highly relevant to the discovery sense of the term. Many of the salient features of good explanations are the same in both, notably: increased predictive power, simplicity, and consilience. (This point is made especially clearly in the work of philosophically trained cognitive psychologists like Tania Lombrozo.) What is not at all clear, however, is that any of the IBE arguments noted above will have the intended impact when the relevant sense of explanation belongs more to what Reichenbach called “the context of discovery” rather than the “context of justification.”

The academic job market is horrible now, after having been unusually good from about 1999-2007. Hopefully it will recover in a few years, though to what extent philosophy departments will participate in that recovery is an open question. Bear these trends in mind when looking at schools' placement records.

The non-academic job market is also horrible now. When the non-academic job market is horrible, graduate school admissions is generally more competitive.

In my posts, I may have somewhat underestimated the importance of the GRE. However, I want to continue to emphasize that different schools, and different admissions committees within the same school over time, take the GRE seriously to different degrees, and thus a low GRE score should by no means doom your hopes. If you have a GRE score that is not in keeping with your graduate school ambitions, I recommend applying to more than the usual number of schools, so that your application will land among at least a few committees that don't give much weight to the GRE.

The original seven posts have comments threads on which you may post questions or comments.